Opera Easter Egg - Undocumented IRC /slap command

- start a chat with the Opera IRC client
- enter a chat room
- write in the text area "/slap <nickname of a person in the room>"
- press Enter
- Opera will "say" on your behalf "/me slaps a large trout around a bit with <nickname>"

This is a reference to mIRC's infamous /slap command ("/me slaps <nickname> around a bit with a large trout")